The present disclosure relates to a liquid crystal display device provided with a liquid crystal display element in which a liquid crystal layer is sealed between a pair of substrates, each of which has an oriented film on a facing surface.
In recent years, liquid crystal displays (LCDs) have been widely used as display monitors of a liquid crystal television receiver, a note-type personal computer, a car navigation apparatus, and the like. Such liquid crystal displays are classified into various display modes (schemes) depending on molecular alignment (orientation) of liquid crystal molecules included in the liquid crystal layer interposed between substrates. As a display mode, a TN (Twisted Nematic) mode in which the liquid crystal molecules are oriented in a twisted manner in a state in which no voltage is applied has been well known, for example. In the TN mode, the liquid crystal molecules have positive dielectric constant anisotropy, namely, a characteristic that a dielectric constant of the liquid crystal molecules in a long axial direction is greater than that in a short axial direction. For this reason, the liquid crystal molecules have a structure in which the liquid crystal molecules are aligned in a perpendicular direction to a substrate surface while an orientation direction of the liquid crystal molecules is subsequently rotated in a plane which is parallel to the substrate surface.
On the other hand, a VA (Vertical Alignment) mode in which the liquid crystal molecules are oriented so as to be perpendicular to the substrate surface in a state in which no voltage is applied has drawn more attention. In the VA mode, the liquid crystal molecules have negative dielectric constant anisotropy, namely, a characteristic that a dielectric constant of the liquid crystal molecules in the long axial direction is smaller than that in the short axial direction, and it is possible to realize a wider viewing angle than that in the TN mode.
A liquid crystal display in the VA mode as described above has a configuration in which light is transmitted by causing the liquid crystal molecules oriented in the perpendicular direction to the substrate to respond to voltage application so as to lie down in a parallel direction to the substrate due to a negative dielectric constant anisotropy. However, since the direction in which the liquid crystal molecules oriented in the perpendicular direction to the substrate lie down is arbitrary, the orientation of the liquid crystal molecules becomes disorganized due to voltage application, which causes deterioration of a responsive characteristic to voltage.
Thus various methods for regulating the orientation of the liquid crystal molecules during voltage application have been proposed hitherto. For example, an MVA (Multi-domain Vertical Alignment) scheme, a PVA (Patterned Vertical Alignment) scheme, or a method using a photo-alignment film (see PTL 1, for example) have been proposed. According to the PVA scheme, a wide viewing angle is realized while the orientation is controlled by using a slit or a rib (protrusion). In addition to this, a structure (also referred to as a fine slit structure) in which a plurality of minute slits are provided in an electrode (specifically, a pixel electrode) formed in one substrate and an electrode formed (specifically, a facing electrode) in the other substrate is formed as a so-called solid electrode with no slit has been recently proposed (see PTL 2, for example). However, the fine slit structure has a problem that transmittance is lowered since a part to which an electric field is not applied is present in a slit including a minute line and a space and further the orientation state of the liquid crystal molecules takes a twisted structure in the vicinity of an edge of the line during voltage application.
A technique to solve such a problem, namely a technique of forming concave and convex portions instead of the plurality of minute slits has been disclosed in PTL 3.